1. Field of the Invention
This invention relates to a cleaning method and apparatus of the particle-blast type. The invention relates more particularly to an improved method and form of blast cleaning apparatus using particles which sublimate after contact with objects being cleaned.
2. Description of the Prior Art
Particle blast cleaning apparatus is well known in the art. Sandblasting equipment is a known example of this type of apparatus. Particles which sublimate can advantageously be used with this form of equipment. Carbon dioxide particles have been used for this purpose. The principal features of this latter type of apparatus is that by sublimation of the carbon dioxide particles from a solid to a vapor phase, an enviromentally cleaner technique is utilized and the labor and expense of clean up which existed with prior apparatus such as the sandblasting equipment is eliminated.
Prior apparatus of this type has exhibited various disadvantages. In one prior apparatus, the sublimable pellets are formed and are supplied at a receiving station to a transport under a vacuum. The pellets are transported to a discharge station and are discharged into a relatively low pressure carbon dioxide stream at a discharge station for transport to a discharge nozzle. Apparatus of this type is substantially complex, costly, difficult to operate and difficult to maintain.